To be able to form and develop competencies with regard to the nature of science (NOS) for students, the teachers must have appropriate conceptions about NOS. Therefore, this study explored levels of conceptions about the nature of science of future physics teachers who have experienced two different physics teachers-education curricula using the survey research methodology. The findings indicated that both curricula have developed positive conceptions of the nature of science for pre-service physics teachers, especially for elements related to creativity in science, subjectivity in science (theory-ladenness), and the tentative nature of scientific knowledge. However, besides good conceptions, naive views could be found in some other elements, such as the purpose of the experiment and the validity of observationally based theories and discipline. Finally, students did not express enough conceptions of the function of scientific theories and the logic of testing them. When differences among generations were investigated, the new generation, who has been experiencing a new curriculum established in 2019, was found to have better conceptions when it came to the scientific definition of science, laws, and theories, as well as scientific methods. However, they hold more inadequate conceptions of the elements of the social and cultural embeddedness of scientific knowledge. These differences were suggested and discussed to be mainly stemmed from the appearance of a course called "Introduction to Natural Science and Technology" in the new curriculum. This paper discusses the implications of this study for investigating NOS conceptions and developing physics teachers-education curricula.